Solids production is a common phenomenon in the petroleum industry. Sand and other solid particles are usually produced to the surface production facilities with the oil, gas and water from the reservoir. This causes several operational problems, such as erosion of upstream equipment, clogging of flowlines and accumulation in the production vessels. Major consequences of these problems could be the reduction in performance of the separator internals and an unplanned shut down of the entire production operation. To avoid such problems, vessel desanding systems are commonly used. In all such systems an accumulation of solids occurs. To remove the solids from the desanding system, the accumulated solids are fluidized by the use of liquid, usually water, and discharged from the system. There are a number of different methods for fluidizing/discharging the solids. Known methods include:
The classic jetting system. The disadvantages of this system are excessive water consumption, large disturbances in process separators, low efficiency of sand removal and risk of clogging.
EP 0802135 A1 discloses a fluidizing unit for fluidizing a non-specified medium. A disadvantage of the disclosed unit is the limited range of operation and thus the quite low efficiency of sand removal.
The aim of the present invention is to provide a fluidizing unit for incorporation in vessel desanding systems which avoids or alleviates at least some of the disadvantages of the prior art techniques.